This letter presents the first piezoelectric micromachined ultrasonic transducer (PMUT) based on thin-film lithium niobate (LiNbO₃). The figures of merit (FoMs) of LiNbO₃ as ultrasound sensors and transducers are first studied, showing great prospective as a balanced transceiver platform. Efficient flexural mode excitation is achieved using a proposed lateral-field-excitation (LFE) structure. The implemented device shows a flexural mode at 7.6 MHz, with a high electromechanical coupling ( $k^{2}$ ) of 4.2%. Measured quality factor ( $Q$ ) in vacuum is 2605, indicating the low structural loss, while measured $Q$ in air is 264, suggesting the ultrasound radiation. A dynamic displacement sensitivity of 20.2 nm/V is measured. Upon further optimizations, LiNbO₃-based PMUTs are promising candidates for miniature ultrasound applications. [2020-0287]

中文翻译：

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JMEMS 推出使用薄膜铌酸锂的压电微机械超声换能器

这封信展示了第一个基于薄膜铌酸锂 (LiNbO ₃ ) 的压电微加工超声换能器 (PMUT )。首次研究了 LiNbO ₃作为超声波传感器和换能器的品质因数 (FoM) ，显示出作为平衡收发器平台的巨大前景。使用建议的横向场激励 (LFE) 结构实现了高效的弯曲模式激励。实现的设备在 7.6 MHz 下显示弯曲模式，具有高机电耦合（ $k^{2}$ ) 的 4.2%。测量的品质因数 ( $Q$ ) 在真空中为 2605，表明结构损失低，而测量 $Q$ 在空气中是 264，表明是超声波辐射。测得的动态位移灵敏度为 20.2 nm/V。经过进一步优化，基于LiNbO ₃的 PMUT 是微型超声应用的有希望的候选者。[2020-0287]